Role of Macrodiols in the Synthesis and Thermo-Mechanical Behavior of Anti-Tack Water Borne Polyurethane Dispersions

Abstract

The texture and molecular weight of polymer drastically affect the adhesion or tack strength. Waterborne polyurethane dispersions (WBPU) have been prepared using two different macrodiols of hydroxyl terminated polybutadiene (HTPB; Mn = 2912 g/mol) and four compositions of Polypropylene glycol (PPG Mn = 425, 1000, 2000, 2700 g/mol). The contents of the macrodiols have been varied using HTPB as 5, 10 and 15 mol%. The prepolymer of HTPB and Poly propylene glycol (PPG) have been developed using 4,4-Methylene bis(cyclohexyl isocyanate) (H12MDI) which is extended using 1, 4 butanediol (BD) followed by the dispersion of polymers in deionized water. Fourier Transform Infra-red spectroscopy (FTIR) is used to confirm the desired PU linkage. The probe tack graphs for tack analysis have not shown any plateau indicating absence of fibrillation. Two different values of glass transition temperature (Tg) have been observed for each dispersion using Differential Scanning Calorimetry(DSC). Storage modulus (E′) up to 3.97 MPa and (tanδ/E′) from 0.01–0.30 MPa−1 has been observed via Dynamic Mechanical Analysis (DMA). Introducing the HTPB has resulted in a decrease in the values of (tanδ/E′). No adhesion favorable parameters have been retrieved, indicating the molar variation a key factor in the development of anti-tack dispersions.

Molecular Dynamics Analysis of Silica/PMMA Interface Shear Behavior

“…In this study, we modeled a notched silica/injected PMMA interface system with MD to investigate the performance of concrete reparation via PMMA injection. Injection simulation results indicate that the notch filling ratio increases with injection pressure (100 MPa-500 MPa) and temperature (200 K-400 K) and decreases with the chain length (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16). During the MD interface sliding tests, the shear stress increased monotonically with strain until the curves exhibited a pseudo-plateau at the onset of damage.…”

“…The stoichiometric mixing ratio of methyl methacrylate and cumene hydroperoxide was 35:1, with a low initial density of 0.5 g/cm3. Molecular Dynamics (MD) models have shed light on the mechanical behavior of numerous polymers and composite materials used to solve multi-physics problems [7][8][9][10][11][12][13][14]. The tensile deformation of bitumen-aggregate and polymer-mineral interfaces was recently investigated through molecular simulations [15][16][17][18].…”

“…The relation between the molecular chain length and the mold cavity geometry was investigated in [30][31][32][33][34], to optimize pattern transfer. Inspired by these previous studies, we compare smooth and rough PMMA/silica interfaces, in which rough interfaces contain a notch of the order of 25 nano-meters in width and Molecular Dynamics (MD) models have shed light on the mechanical behavior of numerous polymers and composite materials used to solve multi-physics problems [7][8][9][10][11][12][13][14]. The tensile deformation of bitumen/aggregate and polymer/mineral interfaces was recently investigated through molecular simulations [15][16][17][18].…”

Cross-linked graphene oxide framework to enhance pervaporation separate property of waterborne polyurethane in food packaging materials

“…Some polymer films such as non-toxic cellulose butyl ester (Nairat et al, 2022), polypyrrole (Ramanavičius et al, 2022), polyvinyl alcohol (Panda et al, 2022), polyethylene (Esmaeili-Faraj et al, 2021), polyester (Rostovtseva et al, 2022), polyurethane (Wu et al, 2022) are used in the membrane of separation. Water-borne polyurethane (WPU) is the only type of polymer that shows both thermos plasticity (Akram et al, 2022) and thermosetting properties in membrane materials (Liu et al, 2019), which has significant advantages in the field of pervaporation membranes.…”

A polyurethane binder with excellent mechanical properties based on copolymerization and dynamic bond crosslinking

“…Its mechanical properties are the key factors to determine the structural integrity of the solid motors, and to a large extent, it relies on the mechanical properties of the matrix binder [9,10]. Because of its high strength, good fluidity, and good adhesion, hydroxyl-terminated polybutadiene (HTPB) is often used in binders [11][12][13]. However, the binder will still have cracks and damage, which will lead to structural safety issues of composite solid propellants, resulting in serious security risks.…”